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Saffari A.,University of Southern California | Daher N.,University of Southern California | Ruprecht A.,Lars Laboratorio Of Ricerca Ambientale Simg Isde | De Marco C.,Tobacco Control Unit | And 7 more authors.
Environmental Sciences: Processes and Impacts | Year: 2014

In recent years, electronic cigarettes have gained increasing popularity as alternatives to normal (tobacco-containing) cigarettes. In the present study, particles generated by e-cigarettes and normal cigarettes have been analyzed and the degree of exposure to different chemical agents and their emission rates were quantified. Despite the 10-fold decrease in the total exposure to particulate elements in e-cigarettes compared to normal cigarettes, specific metals (e.g. Ni and Ag) still displayed a higher emission rate from e-cigarettes. Further analysis indicated that the contribution of e-liquid to the emission of these metals is rather minimal, implying that they likely originate from other components of the e-cigarette device or other indoor sources. Organic species had lower emission rates during e-cigarette consumption compared to normal cigarettes. Of particular note was the non-detectable emission of polycyclic aromatic hydrocarbons (PAHs) from e-cigarettes, while substantial emission of these species was observed from normal cigarettes. Overall, with the exception of Ni, Zn, and Ag, the consumption of e-cigarettes resulted in a remarkable decrease in secondhand exposure to all metals and organic compounds. Implementing quality control protocols on the manufacture of e-cigarettes would further minimize the emission of metals from these devices and improve their safety and associated health effects. This journal is © the Partner Organisations 2014.

Daher N.,University of Southern California | Ruprecht A.,Lars Laboratorio Of Ricerca Ambientale Simg Isde | Invernizzi G.,Lars Laboratorio Of Ricerca Ambientale Simg Isde | De Marco C.,Lars Laboratorio Of Ricerca Ambientale Simg Isde | And 5 more authors.
Environmental Science and Technology | Year: 2011

The association between exposure to indoor particulate matter (PM) and damage to cultural assets has been of primary relevance to museum conservators. PM-induced damage to the "Last Supper" painting, one of Leonardo da Vincis most famous artworks, has been a major concern, given the location of this masterpiece inside a refectory in the city center of Milan, one of Europes most polluted cities. To assess this risk, a one-year sampling campaign was conducted at indoor and outdoor sites of the paintings location, where time-integrated fine and coarse PM (PM2.5 and PM2.5-10) samples were simultaneously collected. Findings showed that PM2.5 and PM2.5-10 concentrations were reduced indoors by 88 and 94% on a yearly average basis, respectively. This large reduction is mainly attributed to the efficacy of the deployed ventilation system in removing particles. Furthermore, PM2.5 dominated indoor particle levels, with organic matter as the most abundant species. Next, the chemical mass balance model was applied to apportion primary and secondary sources to monthly indoor fine organic carbon (OC) and PM mass. Results revealed that gasoline vehicles, urban soil, and wood-smoke only contributed to an annual average of 11.2 ± 3.7% of OC mass. Tracers for these major sources had minimal infiltration factors. On the other hand, fatty acids and squalane had high indoor-to-outdoor concentration ratios with fatty acids showing a good correlation with indoor OC, implying a common indoor source. © 2011 American Chemical Society.

Daher N.,University of Southern California | Ruprecht A.,Lars Laboratorio Of Ricerca Ambientale Simg Isde | Invernizzi G.,Lars Laboratorio Of Ricerca Ambientale Simg Isde | De Marco C.,Lars Laboratorio Of Ricerca Ambientale Simg Isde | And 6 more authors.
Atmospheric Environment | Year: 2012

The correlation between health effects and exposure to particulate matter (PM) has been of primary concern to public health organizations. An emerging hypothesis is that many of the biological effects derive from the ability of PM to generate reactive oxygen species (ROS) within affected cells. Milan, one of the largest and most polluted urban areas in Europe, is afflicted with high particle levels. To characterize its ambient PM, fine and coarse PM (PM 2.5 and PM 2.5-10, respectively) samples were collected on a weekly basis for a year-long period. Samples were analyzed for their chemical properties and ROS-activity. A molecular marker chemical mass balance (MM-CMB) model was also applied to apportion primary and secondary sources to fine organic carbon (OC) and PM. Findings revealed that PM 2.5 is a major contributor to ambient particle levels in Milan, averaging 34.5±19.4μgm -3 throughout the year. Specifically, secondary inorganic ions and organic matter were the most dominant fine PM species contributing to 36±7.1% and 34±6.3% of its mass on a yearly-based average, respectively. Highest PM 2.5 concentrations occurred during December-February and were mainly attributed to poor atmospheric dispersion. On the other hand, PM 2.5-10 exhibited an annual average of 6.79±1.67μgm -3, with crustal elements prevailing. Source apportionment results showed that wood-smoke and secondary organic aerosol sources contribute to 4.6±2.6% and 9.8±11% of fine OC on a yearly-based average, respectively. The remaining OC is likely associated with petroleum-derived material that is not adequately represented by existing source profiles used in this study. Lastly, ROS-activity measurements indicated that PM 2.5-induced redox activity expressed per m 3 of air volume is greatest during January (837μg Zymosan equivalentsm -3) and February (920μg Zymosan equivalentsm -3). Conversely, intrinsic (per PM mass) ROS-activity peaked in July (22,587μg Zymosan equivalentsmg -1 PM) and August (25,161μg Zymosan equivalentsmg -1 PM), suggesting the influence of specific components on oxidant properties of PM. A correlation analysis between ROS-activity and select PM chemical components showed that Ni, Cr, Cu and water-soluble OC are strongly associated with ROS. © 2011 Elsevier Ltd.

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